The HD24 is a directly heated double diode triode that would have been used in broadcast receivers, as detector, AGC detector and first audio amplifier.

The classic envelope is 40 mm in diameter and, excluding the B5 base pins, is 98 mm tall.

 
Pin Connections

B5	1	2	3	4	5	tc
	a	a(d1)	f(-)	f(+)	a(d2)	g1

 
Absolute Maximum Operating Conditions

Triode	Vh	Ah	Va	Vg	mAa	ra	gm
	2.0	0.1	150	-1.5	1.7	28,600	1.4

This exhibit was last updated on 07 February 2003